Lever-type connector with a peak operation resistance shortly before complete connection

Abstract

A lever-type connector has first and second housings ( 10, 20 ) that can be mated with one another. A lever ( 30 ) is mounted rotatably on the first housing ( 10 ). A cam groove ( 35 ) is formed on the lever ( 30 ) and engages a follower pin ( 22 ) on the second housing ( 20 ) to connect the housings ( 10, 20 ). The cam groove ( 35 ) has steep surface area ( 45 ) whose distance from a center of rotation of the lever ( 30 ) decreases at a higher rate than the other areas of the cam groove ( 35 ) and is formed at a position of the cam groove ( 35 ) slightly before a terminus end ( 35 B). Thus, an operation resistance peaks when follower pins ( 22 ) reach the steep surface areas ( 45 ). This peak operation resistance is larger than a sum of a resistance required to engage a lock ( 41 ) with a projection ( 26 ) and a connection resistance acting between housings ( 10, 20 ).

What is claimed is:  
     
       1. A lever-type connector, comprising: 
       first and second housings connectable with each other;  
       a lever pivotably supported on the first housing, the lever having at least one cam surface with a curved shape configured such that a distance from the cam surface to a center of rotation of the lever gradually decreases between a starting end and a terminus of the cam surface;  
       at least one follower provided on the second housing and being engageable with the cam surface so that the housings are connected as the lever is pivoted; and  
       a resistance means on the cam surface for giving a peak operation resistance to the lever when the lever is pivoted to a position reached immediately before the two housings are connected properly and so that operation resistance to the lever decreases continuously from the position of peak operation resistance to a position where the two housings are connected properly.  
     
     
       2. The lever-type connector of  claim 1 , wherein a locking mechanism is provided between the lever and the second housing to lock the two housings together when the two housings reach a properly connected state. 
     
     
       3. The lever-type connector of  claim 2 , wherein the peak operation resistance is larger than a resistance acting when the two connector housings are locked. 
     
     
       4. The lever-type connector of  claim 1 , wherein the resistance means is formed by providing the cam surface with a portion whose distance from the center of rotation decreases in a direction from the starting end to the terminus at a higher rate than at other locations on the cam surface. 
     
     
       5. The lever-type connector of  claim 1 , wherein the resistance means is provided such that the peak operation resistance is reached when the housings have moved through a connection stroke larger than about 80% of a stroke needed to reach the properly connected state of the two housings. 
     
     
       6. The lever-type connector of  claim 5 , wherein the resistance means is provided such that the peak operation resistance is reached when the two housings have moved through a connection stroke less than 95% of a connection stroke needed to reach the properly connected state of the two housings. 
     
     
       7. The lever-type connector of  claim 1 , wherein a starting position locking means is provided on at least one of the lever, the first housing and the second housing to lock the lever temporarily in a starting position where the two housings can be connected with each other. 
     
     
       8. The lever-type connector of  claim 7 , wherein at least one releasing means is provided for releasing the locking function of the starting position locking means when the housings are started to be mated so that the lever can be pivoted. 
     
     
       9. A lever-type connector, comprising: 
       first and second housings connectable with each other;  
       a lever supported pivotally on the first housing, the lever having at least one cam surface with an open starting end, a closed terminus and a curved shape between the starting end and the terminus, the curved shape being configured such that a distance from a center of rotation of the lever to the cam surface gradually decreases between the staring end and the terminus;  
       at least one follower provided on the second housing and being engageable with the cam surface so that the housings are connected as the lever is pivoted; and  
       a resistance means formed on the cam surface closer to the terminus than to the starting end for giving a peak operation resistance to the lever when the lever is pivoted to a position before the housings are connected properly and so that operation resistance to the lever decreases continuously from the position of peak operation resistance to a position where the housings are connected properly.  
     
     
       10. The lever-type connector of  claim 9 , wherein a locking mechanism is provided between the lever and the second housing to lock the housings together when the housings are connected properly, the peak operation resistance being larger than a resistance acting when the connector housings are locked together. 
     
     
       11. The lever-type connector of  claim 10 , wherein the resistance means is a portion of the cam surface where a distance from the center of rotation to the cam surface decreases in a direction from the starting end to the terminus at a higher rate than at other locations on the cam surface. 
     
     
       12. The lever-type connector of  claim 11 , wherein the resistance means is provided such that the peak operation resistance is reached when the housings have moved through a connection stroke larger than about 80% of a stroke needed for the housings to be connected properly. 
     
     
       13. The lever-type connector of  claim 12 , wherein the resistance means is provided such that the peak operation resistance is reached when the two housings have moved through a connection stroke less than 95% of a connection stroke needed for the housings to be connected properly.